In general, inkjet printers include at least one printhead that ejects drops of liquid ink onto a surface of an image receiving member. In an indirect or offset printer, the inkjets eject ink onto the surface of a rotating image receiving member, such as a rotating metal drum or endless belt, before the ink image is transferred to print media. In a direct printer, the inkjets eject ink directly onto print media, which may be in sheet or continuous web form.
In inkjet printers, the printheads are configured with an array of ejectors that are fluidly connected to an array of apertures in a face plate in a one-to-one correspondence. The ejectors are typically piezoelectric or thermal devices that are activated to eject one or more drops of ink from a chamber between the ejector and the aperture to which the ejector is connected. Sometimes, the viscosity of the ink, debris, or other issues can partially or completely block an aperture, the chamber, or the supply of ink to the chamber. To restore the ability of an ejector to eject ink drops through the aperture to which it is connected, printheads are purged. Purging refers to a pressure source being coupled to the pneumatic system within a printhead to urge ink through the chambers in the printheads and emit ink from the apertures of the printhead. This emitted ink is not expelled with sufficient pressure to escape the printhead, but rather remains on the face plate of the printhead.
To remove purged ink from the face plates of printheads, various systems have been developed that heat, wipe, or suction ink from the face plates. Some inks have special properties that make them especially difficult to remove from the face plates of printheads. For example, some printers include printheads that eject magnetic inks. These magnetic inks include solvents that dry quickly once exposed to ambient air and metal particles that can cling to the face plates. Improvements in systems that remove purged ink having special properties that make removal of the ink difficult are beneficial.